The invention relates to gas turbine engine combustion. More particularly, the invention relates to fuel injection systems for aircraft gas turbine engines.
Common gas turbine engines are liquid fueled. In a typical arrangement, the engine's combustor has one or more fuel injectors, each of which has a main passageway with multiple outlets for introducing a main flow of fuel and a pilot passageway for introducing a pilot flow of fuel. The pilot flow is initiated to start the engine and may remain on throughout the engine's operating envelope. The main flow may be initialized only above idle conditions and may be modulated to control the engine's output (e.g., thrust for an aircraft). For variety of performance reasons, it is known to use gaseous fuel (including a vaporized liquid). It is also known to use fuel as a heatsink.